We propose a methodology that searches a region of interest in the 3D point cloud scene for void regions, and analyzes them to either verify that the void region is caused by the occlusion of a detected object or an unidentified obstacle that could be an adversarial hidden object. This approach is different from Shadow-Catcher [1]} as Shadow-Catcher uses the bounding box of a detected object to obtain the shadow region for analysis to detect spoofed objects. With the Object Hiding Attack adversary we consider that the attacker aims to hide the object and thus there is no bounding box for Shadow-Catcher to perform analysis on – Shadow-Catcher is blind to an object hiding adversary. As our approach is unable to identify the objects (i.e. classify and label the object), in the rest of the paper, we call the objects detected by our approach as obstacles. Objects hidden by an adversary will still have shadows in a 3D point cloud, and thus can still be detected as an obstacle by our methodology.
